Pump unit for the transportation of liquids

ABSTRACT

Centrifugal pump unit for transportation of liquids having an outlet conduit in communication with a pump housing in which an impeller is located. The arrangement is provided whereby liquid in the pumphousing which provides a seal between the impeller and the walls of the pumphousing will not be discharged from the pump unit before liquid to be pumped flows into the pumphousing via a feeding conduit.

' 1 Dec. 24, 1974 I g? 513 THE TRANSPORTATION FOREIGN PATENTS OR APPLICATIONS Q 601,653 5/1948 Great Britain........V....I......... 415/53 Carl Bruno Pettersson, Smedjegatan Sweden Primary ExaminerWilliam L. Freeh Man 26 1973 Assistant Examiner-L. J. Casaregola [57] ABSTRACT Centrifugal pump unit for transportation of liquids U.S. 415/53,4l7/900 having an Outlet conduit in communication with a 51] Int. F041 5/00 P p housing in which an impeller is located- The 5 53 11, 7; 17 0 rangement is provided whereby liquid in the pumphousing which provides a seal between the impeller R f n e Cited and the walls of the pumphousing will not be dis- UNITED STATES PATENTS charged from the pump unit before liquid to be 8/1945 pumped flows into the pumphousing via a feeding conduit.

United States Patent Pettersson [76] Inventor:

[22] Filed:

[211 App]. No.: 344,997

[58] Field of Search...........

alt iii/1595155147 .IL

lllllTl/llllltl Longenecker Kabele..................... Speck et a1.

PUMP UNIT FOR THE TRANSPORTATION OF LIQUIDS The present invention relates to a centrifugal pump unit for the transportation of liquids.

It is a purpose of the present invention to provide a pump unit of the kind mentioned by means of which it is possible to lift a liquid intended for pumping, in a very speedy way even if the feeding conduit should be empty, while at the same time, liquid in the pumphousing, serving the purpose of sealing the impeller, will not be discharged from the pump unit before liquid to be pumped has begun to flow into the pumphousing via the feeding conduit.

This purpose has been reached by the object of the invention the characteristics of which are evident from the claims.

In the following description a pump unit made according to the invention will be described with reference to the accompanying drawings, in which FIG. 1 illustrates a vertical cross-section of the pump unit along a plane congruent with a plane through the pump axis',

FIG. 2 is a perspective view of the pump unit with the impeller and the wall of the pump unit which supports said impeller removed; and

FIG. 3 is a perspective part view corresponding to FIG. 2 of the pump unit according to an alternative embodiment of the invention.

In the drawing numeral 1 indicates the housing of a centrifugal pump of conventional design, i.e., comprising an excentrically positioned impeller 2, at the centre of which an inlet opening 3 is arranged to receive the liquid to be pumped, and an outlet tube 4 extending substantially in a vertical direction from the periphery of the pumphousing, said tube extending in a direction substantially tangentially to the pumphousing 1. In the pump unit made according to the invention, the pumphousing via the inlet opening 3 communicates with an antechamber 5 into which an inlet conduit 6 leading into the pump unit debouches. The inlet conduit 6 is provided with a flange 7, which by means of bolts 8 is fastened to an outer wall 9 of the pump unit.

The antechamber 5 is defined by means of a wall portion 10 which constitutes one of the end walls of the pumphousing. The opposite end wall of the pumphousing comprises the outer wall 11 of the pump unit which is located at the opposite side relative to the outer wall 9. Between the end walls 9 and 11 of the pump unit extends a third outer wall 12, which down in the lower portion comprises the peripheral wall of the pumphousing as shown in FIG. 2. The upper wall of the pumphousing is indicated at 13 and extends in an are from one wall 14 of the outlet tube 4 to the portion of the outer wall 12 which is located at the opposite side of the pumphousing in a diametrical direction thereof.

Surrounding the antechamber 5 there is an additional chamber 15 which is separated from the pumphousing by means of a wall 13 and from the antechamber 5 by means of a projecting portion of the end wall 10 of the pumphousing l and an additional wall 16 extending between said end wall and the outer wall 9 of the pump unit.

The impeller 2 which can be of conventional design is rotatably supported by the outer wall 11 of the pump unit via a roller bearing 18 which is mounted in a bearing cage 19, which in turn by means of bolts 20 is fastened to a flange 21, which in turn is fastened to the outer wall of the pumphousing by means of bolts 22. The chamber 15 which extends around the antechamber 5, communicates in its lower portion with the pumphousing 1 via holes 23 in the partition wall 10, and in its upper portion chamber 15 communicates with the outlet tube 4 via two openings 24 and 25 respectively located at different levels in wall 14 as shown in FIG. 2. Between the openings 24 and 25, in a vertical direction, a side valve plate 26 is arranged in the outlet tube 4, said plate being pivotably mounted about a horizontal axis 27 parallel to the wall 14 and located close to said wall. By way of example, the valve plate 26 by means of a spring (not shown in the drawing) is biased by a force tending to keep the same in the position illustrated in FIG. 2 transverse to the outlet tube 4, in which position the upper and lower portions of the outlet tube are in communication with each other via the openings 24 and 25 and the chamber 15. The force tending to close the valve plate 26 is comparatively weak, so that an upwards pivoting of the same takes place as soon as it is subjected to a pressure of any note of a liquid from below.

The inner end of the inlet tube 6 is somewhat beveled as is shown in FIG. 1 and provided with a flange 37 which, in its upper part by means of a bolt 28 supports a disc 29 of resilient material, for example rubber, serving the purpose of a check valve. The disc 29 is stiffened by means of two stiff discs 30 and 31 respectively, arranged at each side of the same which discs are kept tightly pressed against the disc 29 by means of a centric bolt 32. Because of the mentioned bevel, the valve body 30 32 on account of its own weight tends to lie against the flange 37 of the inlet tube.

An inspection door 33 is by means of bolts 34 fastened to the outer wall 9 and it covers an inspection opening 35 leading to the lower portion of the chamber 15. A filler plug 36 is arranged in the upper portion of the wall 12 of the pump unit.

If, before it is put into use, the pump unit does not hold any liquid, such liquid is filled through that opening in the upper portion of the pump unit which is uncovered by the removal of the filler plug 36. The liquid filled streams via the openings 23 26 downwards into the pumphousing 1 and possibly also into the antechamber 5. When the impeller 2 is set in rotation the liquid in the pumphousing will provide a seal between the impeller and the walls of the pumphousing. During this first stage of the pumping operation the valve plate 26 is in the position illustrated in FIG. 2 which means that liquid is pumped through the opening 24 into the chamber 15, from which a return flow takes place to the pumphousing via the openings 23, while the air following with the water is being separated and streams out via the opening 25. When liquid begins to stream in via the inlet tube 6, a rise of the level of the liquid takes place in the chamber 15, and the force operating from below upon the valve plate 26 forces the same to swing open and pumped liquid streams through the outlet tube 4.

Thus, in the pump unit according to the invention a pumping out of air appearing in the inlet tube takes place without the liquid in the pumphousing 1 and in the chamber 15 also being pumped outwhich in case it happened, would cause a very bad suction effect. As is evident from FIG. 1, due to the edge of the inlet opening 3 of the pumphousing being located at a distance from the antechamber wall 16, straw and the like which, for example, may be fed into the chamber together with the liquid, is torn apart on account of the difference in flow velocity of the liquid in the antechamber and the pumphousing respectively. This makes the pump unit especially advantageous, when pumping for example, liquid contained in manure which has not been freed from straw and the like.

According to the embodiment shown in FIG. 3 an additional valve plate 38 is mounted on the axle 27 inside the chamber and located in a plane parallel to the plane of the valve plate 26. The distance between the plane of the lower side of the valve plate 38 and the upper side of the valve plate 26 corresponds to the thickness of the partition wall 14. Thus the valve assembly will cover both the opening 25 and the opening 24 when being pivoted 90 in clockwise direction from the position shown in FIG. 3. This will give the pump a still higher efficiency than with the single valve plate according to the embodiment shown in FIG. 1 and 2.

The invention is not limited to the embodiments illustrated in the drawings and described above by way of example only, but can be varied as to its details within the scope of the claims. Thus, by way of example the lower wall 16 of the antechamber 5 can be located at a lower level than the ones illustrated in the drawings without departing from the fundamental idea of the invention.

I claim:

1. Centrifugal pump unit for pumping of liquids, comprising a pump housing, an impeller located in said housing, an outlet conduit in communication with said pump housing, said outlet conduit extending in an upwardly direction and having a side wall with a first opening at a comparatively high location relative to the pump housing, a chamber for receiving liquid in communication with said first opening, said chamber being in communication with said pump housing via additional openings in a Wall of said pump housing, a second opening in said side wall of said outlet conduit at a higher level than said first opening, said second opening establishing communication between said outlet conduit and the upper portion of said chamber, and a valve plate pivotally mounted in said outlet conduit between said first and second openings, said valve plate normally extending transverse to said outlet conduit to close same when the pressure in said outlet conduit is comparatively low, and pivotable to a position substan tially parallel to said side wall to open said outlet conduit when said pressure approaches the working pressure of the pump.

2. Pump unit according to claim 1, wherein said valve plate is movable to cover said second opening when it is pivoted to its position substantially parallel to said side wall.

3. Pump unit according to claim 2, having a second valve plate extending away from and along a plane substantially parallel to the first said valve plate, said second valve plate being fixedly mounted on a common axle with the first said valve plate and being located in the chamber, said second valve plate being movable to cover said first opening when the first said valve plate is movable to cover said second opening. 

1. Centrifugal pump unit for pumping of liquids, comprising a pump housing, an impeller located in said housing, an outlet conduit in communication with said pump housing, said outlet conduit extending in an upwardly direction and having a side wall with a first opening at a comparatively high location relative to the pump housing, a chamber for receiving liquid in communication with said first opening, said chamber being in communication with said pump housing via additional openings in a wall of said pump housing, a second opening in said side wall of said outlet conduit at a higher level than said first opening, said second opening establishing communication between said outlet conduit and the upper portion of said chamber, and a valve plate pivotally mounted in said outlet conduit between said first and second openings, said valve plate normally extending transverse to said outlet conduit to close same when the pressure in said outlet conduit is comparatively low, and pivotable to a position substantially parallel to said side wall to open said outlet conduit when said pressure approaches the working pressure of the pump.
 2. Pump unit according to claim 1, wherein said valve plate is movable to cover said second opening when it is pivoted to its position substantially parallel to said side wall.
 3. Pump unit according to claim 2, having a second valve plate extending away from and along a plane substantially parallel to the first said valve plate, said second valve plate being fixedly mounted on a common axle with the first said valve plate and being located in the chamber, said second valve plate being movable to cover said first opening when the first said valve plate is movable to cover said second opening. 